Current corrosion protection systems utilize packaging materials made of polymeric-films with very low-to-zero water vapor transmission rates (WVTR), polymeric films which are impregnated with volatile corrosion inhibitors (VCI), paper packaging which are coated or impregnated with VCI, VCI capsules and emitters and also metallic, plastic, wooden, and cardboard boxes containing dehumidifiers such as desiccants.
Typically, corrosion protection is provided by VCI impregnated packaging polymeric films with various WVTR from very high (breathing film) to zero WVTR (barrier film), as well as absorbent media such as capsules and emitters. Depending on the packaging requirements, some packaging systems are subjected to nitrogen gas blanket to prevent oxidation and also vacuum to eliminate the availability of oxygen and humidity. These packaging systems are costly in terms of materials and processes due to manpower required and other technical steps required.
Often, existing packaging and other enclosure systems are not efficient because of the following reasons:
They provide only a constant amount of a fixed type of VCI in spite of continuously changing environmental and climate conditions as well as concentration of corrosion-causing chemicals/molecules in air.
Most of the articles have parts made of different metals, e.g., low carbon alloy, stainless steel, copper, aluminum, magnesium and different alloys based on these metals, galvanized (zinc, nickel, chromium, etc.) parts, etc., requiring different types of VCI to achieve corrosion protection.
Metallic equipment can contain fabrics/cloths/woods that can absorb water. The same can also create corrosion problems when the temperature increases and decreases due to evaporation and condensation.
Metal parts with different thicknesses have corrosion that occurs due to the dependency of the rate and level of water vapor condensation on thick metal as a function of rate of temperature change.
When the thickness of condensed vapor increases; the corrosion rate can increase due to the insufficient level of corrosion inhibitors.
In life, one of the well known facts is that environmental and weather conditions will continuously vary during any given journey, whether it is on land and/or overseas. More-over, the weather conditions will always vary at different geographical locations and different times throughout the day and night during the journey. Global distribution of metallic materials require continuous protection with respect to varying and unpredictable environments, changing temperatures (T) and relative humidity (RH), and different corrosion causing gaseous molecules/chemicals in the enclosure environment. Various articles such as parts and equipment are subjected to corrosive environments for long durations at these varying corrosive conditions. Current technologies and products are not always effective for corrosion protection since they generally have a limited life with respect to corrosion protection and/or prevention systems that generally provide VCI only through VCI paper, VCI film, and/or other devices that use fixed amounts of any one type of VCI. Moreover, packaging of the article is prepared for the entire journey from the original point to the final destination using fixed types and amounts of VCI. The VCI formulation used is supposedly a universal type which does not take into consideration variable metals, environmental and climate conditions. Stationary metal articles such as those used on machines, equipment and the like also encounter similar problems as the weather conditions can change from dry to heavy rains, excessive humidity, night and day conditions, and the like. Such enclosures are often not sealed off with respect to the environment, thus promoting corrosion.